This application claims priority to Japanese patent application number 2001-195282 filed Jun. 27, 2001, the contents of which are hereby incorporated herein by reference.
1. Technical Field
The present invention relates to angle drills that have a housing and a handle adapted to be held by an operator.
2. Description of the Related Art
Angle drills are known that have a tubular motor housing and a gear housing. A motor is disposed within the motor housing. A spindle is rotatably supported within the gear housing and extends in a direction perpendicular to the output shaft of the motor. The rotational torque of the motor is transmitted to the spindle via a bevel gear. A drill bit may be mounted on the spindle, so that the drill bit rotates when the motor is started.
A handle is mounted on the rear portion of the motor housing and has the same axis as the longitudinal axis of the motor housing. A switch lever is mounted on the handle for starting and stopping the motor. A grip is attached to the motor housing. Therefore, the operator can perform a drilling operation by operating the switch lever while he or she holds the handle and the grip with both hands.
However, in the known angle drills, the axis of the spindle is fixed relative to the handle. Therefore, if the angle drill is used to be operated within a narrow space or is used to be operated with the spindle oriented toward a desired direction, it is difficult in some cases for the operator to properly hold the handle and operate the switch lever. Therefore, the known angle drills have a problem in operability.
U.S. Pat. No. 5,201,146 in the name of the same assignee as the present application teaches a disk grinder that has a motor housing and a handle that is rotatably coupled to the motor housing at a joint portion. The handle can be fixed in position in the rotational direction by means of a bolt that extends through the joint portion. In order to change the rotational position of the handle, the operator loosens the bolt and rotates the handle to a desired position. Then, the bolt is tightened to fixed the handle relative to the motor housing.
Therefore, it is one object of the present teachings to provide improved angle drills. For example, in one aspect of the present teachings, angle drills may have a housing that accommodates a motor. A handle may be rotatably coupled to the housing and may be adapted to be held by an operator. Therefore, the rotational position of the handle can be changed in response to various operating conditions, e.g. places of use of the angle drills and postures of the angle drills during the operation, so that the operator can properly hold the handle during the drilling operation.
According to another aspect of the present teachings, a lock device is operable to selectively lock and unlock the handle relative to the housing with regard to the rotational direction. Therefore, the operator can lock the handle in the desired position and can unlock the handle to rotate the handle to another rotational position without need of any additional tools.
According to another aspect of the present teachings, the lock device may includes a lock button and a plurality of engaging recesses. The lock button may be mounted on one of the housing and the handle and the engaging recesses formed in the other of the housing and the handle. The engaging recesses may be spaced from each other in the rotational direction, so that the lock button can engage either one of the engaging recesses for locking the handle with regard to the rotation. Therefore, the handle can be reliably locked at plural positions through engagement of the lock button with the engaging recesses. In addition, the locking and unlocking operations can be easily performed by simply moving the lock button.
Preferably, the lock button may be mounted on the handle and the engaging recesses may be formed in the housing. The lock button may be disposed adjacent to a switch lever that also may be mounted on the handle for starting and stopping the motor. The lock button and the switch lever may be positioned such that the operator can operate the lock button and the switch lever while he or she holds the handle.
Additional objects, features and advantages of the present invention will be readily understood after reading the following detailed description together with the accompanying drawings and the claims.